Waterpumps affect on engine rpm

[kifried]

Hey guys, this is a super general question. In my daily driver a 98 grand am, the engine is suddenly idling very high around 3000rpm. Coincidentally I think my water pump has gone bad. Is it possible for the lack of pressure from the water pump to cause a full injected car to rev higher? My father said that it's typical for the idler switch, I guess some sensor or switch that controls idle speed is something that normally fails on this car.

any input would be great.

Thanks

 

[megaladon6]

when the pumps go bad its usually a bad bearing. this would cause more load and lower RPM's. i'm going to guess that the IAC may be fouled or the TPS is bad. are there any codes in the computer?

 

[kifried]

so lower rpm then but definitely not higher rpm? I'm trying to determine if there is some correlation between the super high idle and the water pump or if it's coincidentally 2 separate issues that happened at the same time.

 

[megaladon6]

i highly doubt that therea ANY correlation between the 2. is the check engine light on? if so post the codes.

 

[kifried]

the check engine light is not on but the low coolant light is. I just got back from autozone, topped the coolant, also got some Bar's Leak, and now the engine rpm is normal in all gears. very odd..

 

[megaladon6]

ok. i've seen some weird stuff happen with bad w-pumps but never 3k idles. obviously i haven't seen it all though. good catch.

 

[kifried]

Talked with my father (he has been selling NOS GM parts for the past 33 years). Anyway his theory is that because the coolant was sooooo low, the Coolant Temp. Sensor wasn't coming into contact with any Fluid, therefore it wasn't sensing any temp, and somehow, the details are sort of unknown, from that, the feedback to the computer was to idle high.

All very odd if you ask me. I hate computers ha

 

[megaladon6]

yeah i though of that, but i haven't seen it cause THAT high of an idle. i've seen it cause a fluctuating idle. but obviously it was something along those lines. i used to love when we got those problems in the shop because i learned a lot from reading the data stream.